Semiconductor device and inspection method of semiconductor device and wireless chip

ABSTRACT

The invention provides an inspection method of a semiconductor device which receives a test program wirelessly. As an inspection method of the semiconductor device, a test program is transmitted as a communication signal for every test. By transmitting a test program as a communication signal wirelessly in the case of an operation test, test contents are changed as required. As a result, a test program can be easily changed and an inspection circuit or the like is not required. In this manner, manufacturing cost of a wireless chip can be reduced.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an inspection method for simply inspecting asemiconductor device and a structure of a semiconductor device.

2. Description of the Related Art

In recent years, for various fields that require automaticauthentication such as securities and inventory control of products, acard mounting an RFID (Radio Frequency Identification) chip or an RFIDtag that is capable of giving and receiving data wirelessly areincreasingly required. A card mounting an RFID chip has a larger memorycapacity and is superior in security than a magnetic card which storesdata by a magnetic recording method. Therefore, in recent years, modesof the card mounting an RFID chip that can be used for various fieldshave been suggested. Such a card mounting an RFID chip communicates datathrough an antenna having a suitable shape for a frequency band to beused for giving and receiving data; thereby data is read or writtenwirelessly with external devices.

In general, a semiconductor device such as an RFID tag is mass-producedand shipped after an inspecting process. As one of the inspectionmethods, there is a method to perform an inspection without supplying adriving power to a circuit or a substrate (see Patent Document 1).Patent Document 1 discloses a method in which an inspection circuit isincorporated in an integrated circuit in advance, a unique code is givento the inspection circuit, an operation power source is generated byreceiving electromagnetic waves from outside, inspection is performed inaccordance with a procedure based on the generated inspection signals,and the inspection result is transmitted to outside.

As another inspection method, there is a method to inspect the wholesubstrate including wiring patterns wirelessly (see Patent Document 2).Patent Document 2 discloses a method in which an inspection circuit isincorporated in an integrated circuit in advance, a unique code is givento the inspection circuit, a driving power for the inspection circuit isgenerated by receiving electromagnetic waves by a reception portion ofthe inspection circuit, an inspection control procedure is wirelesslyreceived from the inspection device similarly, and the result istransmitted to the inspection device.

Patent Document 1

Japanese Patent Laid-open No. 2003-57300

Patent Document 2

Japanese Patent Laid-open No. 2003-60047

SUMMARY OF THE INVENTION

In a conventional semiconductor device, a major inspection method was tomount an inspection circuit in the semiconductor device and carry outthe inspection of the semiconductor device using the inspection circuit.However, in this method, the inspection circuit has to be changed forevery change or update of a test program required for the inspection,which makes the change or update extremely difficult.

In view of the aforementioned, in the invention, a test programtransmitted by wireless communication is stored in a data storingportion mounted in the semiconductor device, thereby the inspection iscarried out by using the test program. The test program can be changedin accordance with a required inspection by erasing or writing throughwireless communication. As the semiconductor device, a chip capable ofwireless communication (hereinafter referred to as a wireless chip) canbe suggested.

Hereafter, specific configurations of the invention is described.

One mode of the invention is a semiconductor device which includes adata storing portion and an antenna. The data storing portion includes athin film transistor. The data storing portion stores a test programreceived through an antenna by wireless communication at least in a teststep.

Another mode of the invention is a semiconductor device which includes adata storing portion, a reception circuit, a state control register, andan RF circuit. Each of the data storing portion, the reception circuit,the state control register, and the RF circuit includes a thin filmtransistor. The data storing portion stores a test program processed bythe reception circuit after being received through the RF circuit bywireless communication at least in a test step, thereby the statecontrol register becomes a test program execution state.

Further, the state control register may have a unit for rewriting a testprogram execution state flag into a test program execution state.

The data storing portion includes a read only memory and a random accessmemory.

The test program includes data containing a test routine for carryingout an operation test of the read only memory and the random accessmemory.

In the aforementioned mode including an arithmetic circuit and atransmission circuit, the arithmetic circuit may have a function tostart the test program before the state control register changes into atest program execution state, change the state control register into atransmission processing state when the test program is terminated,output the transmission data processed by the transmission circuit so asto be suitable for the form of communication signals, and change thestate control register into a reception processing state when thetransmission is terminated.

Another mode of the invention is an inspection method of a semiconductordevice including an arithmetic circuit, a data storing portion, areception circuit, a state control register, and an RF circuit. Thearithmetic circuit starts an operation in accordance with a state of thestate control register. The arithmetic circuit reads a test programstored in the data storing portion and executes a test routine in thetest program. The arithmetic circuit determines an execution result ofthe test routine and writes it to the data storing portion. The testprogram is processed by the reception circuit after being received as acommunication signal through the RF circuit.

Another mode of the invention is an inspection method of a semiconductordevice including an arithmetic circuit, a data storing portion, areception circuit, a state control register, an RF circuit, and atransmission circuit. The test program is started when the state controlregister changes into a test program execution state. The arithmeticcircuit reads a test program stored in the data storing portion andexecutes a test routine in the test program. The arithmetic circuit hasa function to determine an execution result of the test routine, writethe execution result to the data storing portion, change the statecontrol register into a transmission processing state when the testprogram is terminated, output the transmission data processed by thetransmission circuit so as to be suitable for the form of communicationsignals to a modulation circuit, and change the state control registerinto a reception processing state when the transmission is terminated.The test program is processed by the reception circuit after beingreceived as a communication signal through the RF circuit.

In the aforementioned mode of the inspection method, the state controlregister may be changed into a transmission processing state by a unitfor rewriting a reception state flag into an executing state.

Another mode of the invention is an inspection method of a wireless chipincluding an arithmetic circuit, a state control register, a datastoring portion, an RF circuit, and a reception circuit. A liquidcrystal element is provided on the wireless chip. A test program isprocessed by the reception circuit and stored in the data storingportion after being received as a communication signal through the RFcircuit. The inspection result carried out by the test program isdisplayed by the liquid crystal element.

Another mode of the invention is an inspection method of a wireless chipincluding an arithmetic circuit, a state control register, a datastoring portion, an RF circuit, and a reception circuit. A liquidcrystal element is provided on the wireless chip. The wireless chip isplaced between a laser light source and a light receptor. A test programis processed by the reception circuit and stored in the data storingportion after being received as a communication signal through the RFcircuit. The inspection result carried out by the test program isdetermined by whether light from the laser light source is inputted tothe light receptor or not.

In the aforementioned inspection method of a wireless chip, the liquidcrystal element may be formed of substrates provided with polarizingplates, which sandwich liquid crystal molecules.

By the invention, a power source voltage is supplied by an inducedelectromotive force of a communication signal. In a wireless chip whichtransmits and receives communication data, a test program is transmittedfor every test as a communication signal in the case of an operationtest of a component of the wireless chip. As a result, test contents canbe flexibly changed as required. In this manner, manufacturing cost ofthe wireless chip can be reduced.

By forming a wireless chip of the invention using a thin film transistorformed of a semiconductor thin film as an active layer, which is formedover a substrate having an insulating surface, such as a glasssubstrate, a quartz substrate, and a plastic substrate, a highlyfunctional and low power consumption wireless chip can be provided.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing a semiconductor device of theinvention.

FIG. 2 is a flow chart showing an inspection method of the invention.

FIG. 3 is a flow chart showing an inspection method of the invention.

FIG. 4 is a view of an inspection device of the invention.

FIG. 5 is a display example of an inspection result of the invention.

FIG. 6 is a view of an inspection device of the invention.

FIG. 7 is a view of an inspection object of the invention.

FIG. 8 is a view of an inspection object of the invention.

FIG. 9 is a block diagram showing a semiconductor device of theinvention.

FIG. 10 is a view of an operation of liquid crystal elements applied tothe invention.

FIG. 11 is a view of an operation of liquid crystal elements applied tothe invention.

FIG. 12 is a sectional view of liquid crystal elements applied to theinvention.

FIG. 13 is a flow chart showing an inspection method of the invention.

FIGS. 14A and 14B are views showing an inspection device and aninspection object of the invention.

FIGS. 15A to 15E are views showing manufacturing steps of asemiconductor layer of the invention.

FIG. 16 is a flow chart showing an inspection method of the invention.

FIG. 17 is a flow chart showing an inspection method of the invention.

FIG. 18 is a flow chart showing an inspection method of the invention.

FIG. 19 is a flow chart showing an inspection method of the invention.

FIG. 20 is an address space included in a semiconductor device of theinvention.

FIGS. 21A and 21B are data modes of a test program of the invention.

FIG. 22 is a block diagram showing an inspection device of theinvention.

FIG. 23 is a flow chart showing an inspection method of the invention.

FIG. 24 is a block diagram showing a semiconductor device of theinvention.

FIG. 25 is a block diagram showing a semiconductor device of theinvention.

FIG. 26 is a sectional view of a semiconductor device of the invention.

FIGS. 27A to 27D are views of shapes of an antenna included in asemiconductor device of the invention.

FIGS. 28A to 28C are diagrams showing results of measurements carriedout by the invention.

DETAILED DESCRIPTION OF THE INVENTION

Although the present invention will be fully described by way ofembodiment modes with reference to the accompanying drawings, it is tobe understood that various changes and modifications will be apparent tothose skilled in the art. Therefore, unless such changes andmodifications depart from the scope of the invention, they should beconstrued as being included therein. Note that identical portions inembodiment modes are denoted by the same reference numerals and detaileddescriptions thereof are omitted.

Embodiment Mode 1

This embodiment mode describes a block diagram of a wireless chip as aninspection target of the invention, a device configuration, and a flowchart for realizing an inspection method of a wireless chip.

FIG. 1 is a block diagram of a wireless chip as an inspection target ofthe invention.

In FIG. 1, a wireless chip 201 includes a data storing portion 221, anarithmetic circuit 202, a state control register 203, a receptioncircuit 204, a transmission circuit 205, an antenna 206, a resonantcircuit 207, a power source circuit 208, a reset circuit 209, a clockcircuit 210, a demodulation circuit 211, and a modulation circuit 212.The wireless chip 201 can transmit and receive a reception signal 213and a transmission signal 214 by an RF circuit including the antenna206, the resonant circuit 207, the power source circuit 208, the resetcircuit 209, the clock circuit 210, the demodulation circuit 211, andthe modulation circuit 212. It is to be noted in FIG. 1 that thereception signal 213 and the transmission signal 214 are shown asdifferent signals for simplicity; however, they are actually overlappedand simultaneously transmitted and received between the wireless chip201 and a reader/writer.

In FIG. 1, when the wireless chip 201 is placed in a magnetic fieldformed by a communication signal, an induced electromotive force isgenerated by the antenna 206 and the resonant circuit 207. By theinduced electromotive force, a power source voltage of the wireless chip201 can be supplied. The induced electromotive force is held in electriccapacitance of the power source circuit 208, which can stabilize apotential. The reset circuit 209 generates a system reset signal 215which initializes the whole wireless chip 201. The system reset signal215 has a clock waveform. For example, a signal which rises with acertain delay with respect to a rise of a power source voltage can beused as the system reset signal 215. The clock circuit 210 generates aclock signal from a communication signal. For example, when thecommunication signal passes through an inverter circuit after beingrectified by a half-wave rectifying circuit, a clock signal having thesame cycle as the communication signal can be generated. This clocksignal may be used as a system clock signal 216 in the wireless chip 201or may further be divided to be used as the system clock signal 216. Thedemodulation circuit 211 detects a change in amplitude of the receptionsignal 213 as a signal “0” or “1”. As the demodulation circuit 211, forexample, a low pass filter is used. The modulation circuit 212 transmitstransmission data by changing amplitude of the transmission signal 214.For example, in the case where transmission data is “0”, a resonantpoint of the resonant circuit 207 is changed to change amplitude of acommunication signal. The state control register 203 shows a receptionprocessing state, a data executing state, or a transmission processingstate. By changing the state control register 203, transition among theaforementioned states can be realized. In specific, a specific bit ofthe state control register 203 is set as a reception processing stateflag bit, a test program executing state flag bit, or a transmissionprocessing state flag bit. For example, when each state flag bit is “1”,each state is obtained. That is, in this case, when the receptionprocessing state flag bit is “1”, the wireless chip 201 is in areception processing state.

The data storing portion 221 includes a memory element which stores testprogram data and a test result contained in reception data received fromthe reader/writer. As the memory element, a read only memory (ROM) or arandom access memory (RAM) can be used. ROM includes a mask ROM (ReadOnly Memory) or the like while RAM includes an SRAM (Static RandomAccess Memory) or the like. In specific, the test program data containsa test routine for carrying out an operation inspection of the ROM orRAM and the inspection result contains a defective address and defectinformation of the ROM or RAM.

In the reception processing state, the reception circuit 204 operatesand the arithmetic circuit 202 and the transmission circuit 205 stopoperations. Moreover, in the arithmetic processing state, the arithmeticcircuit 202 operates and the reception circuit 204 and the transmissioncircuit 205 stop operations. Further, in the transmission processingstate, the transmission circuit 205 operates and the reception circuit204 and the arithmetic circuit 202 stop operations.

In order to stop a clock signal supply in the aforementioned statecontrol, for example, an enable signal 217 of a clock signal supplied tothe reception circuit 204 when the reception processing state flag bitis “1”, a reset signal of the arithmetic circuit 202 is set “0” and anenable signal 218 of a clock signal supplied to the arithmetic circuit202 is set “1” when the arithmetic processing state flag bit is “1”, andan enable signal 219 of a clock signal supplied to the transmissioncircuit 205 is set “1” when the transmission processing state flag bitis “1”.

More specifically, logical multiplication of the system reset signal 215and the enable signal 217 is used as a clock signal supplied to thereception circuit 204 and logical multiplication of the system resetsignal 215 and the enable signal 218 is used as a clock signal suppliedto the arithmetic circuit 202, and logic multiplication of the systemreset signal 215 and the enable signal 219 is used as a clock signalsupplied to the transmission circuit 205.

By supplying a clock signal to only a required circuit as describedabove, power consumption of the whole wireless chip can be reduced.

Hereafter, an operation of the whole wireless chip is described withreference to the flow chart of FIG. 2.

The reception circuit 204 identifies and extracts SOF (Start Of Frame),reception data, and EOF (End Of Frame) from a signal demodulated by thedemodulation circuit 211 (communication signal reception 271). In thecase where EOF is extracted, reception data is stored in the datastoring portion 221 and the state control register 203 is changed into atest program executing state (state control register setting 272). Inorder to change the state control register 203 into a test programexecuting state, a unit for rewriting the test program executing stateflag into “1” is to be provided. In specific, when the reception circuitextracts EOF, the reception circuit 204 is to have a unit for changingthe test program executing state flag into “1”.

The arithmetic circuit 202 includes a dedicated circuit for executing atest program, for example, in transmitting and receiving test programdata. When the test program executing state flag is “1”, the testprogram is started (test program execution 273). Further, when the testprogram is terminated, the state control register is changed into atransmission processing state (state control register setting 274). Inorder to change the state control register 203 into a transmissionprocessing state, a unit for rewriting the transmission state flag into“1” is to be provided. In specific, when the arithmetic circuit 202terminates execution of the test program, the arithmetic circuit 202 isto have a unit for changing the transmission state flag into “1”.

The transmission circuit 205 processes transmission data in accordancewith the form of the communication signal and outputs it to themodulation circuit 212 (communication signal transmission 275). When thetransmission is terminated, the state control register is changed into areception processing state (state control register setting 276). Inorder to change the state control register into the reception processingstate, a unit for rewriting the reception state flag into “1” is to beprovided. In specific, when the transmission circuit 205 terminatestransmitting transmission data, the transmission circuit 205 is to havea unit for changing the reception state flag into “1”.

Next, description is made of an operation of a test program withreference to the flow chart of FIG. 3.

The arithmetic circuit 202 starts an operation by receiving a state ofthe state control register 203 (start 307). The arithmetic circuit 202reads a test program from the data storing portion 221 (test programreading 308) and executes a test routine in the test program (testroutine execution 309). The arithmetic circuit 202 determines anexecution result of the test routine test result determination 310 andwrites the results in the data storing portion 221 (test result writing311). At last, the arithmetic circuit 202 terminates the operation(termination 312).

By executing the test program in this manner to transmit the testprogram as a communication signal for every test, test contents can befreely changed as required.

Next, description is made with reference to FIGS. 4 to 8 on aninspection device of a wireless chip which has the configuration of FIG.1 and operates in accordance with the procedures of FIGS. 2 and 3.

A substrate 404 shown in FIG. 4 is a large glass substrate over which alarge number of wireless chips are formed. The wireless chip has aconfiguration as shown in FIG. 1. In specific, in the case of using afourth generation glass substrate having a size of 600 mm×720 mm, about4000 wireless chips each having a size of 1 cm square can be formed overone substrate. FIG. 7 shows a top plan view of the substrate 404. Eachof the wireless chips has an antenna 406. By the antenna 406, wirelesscommunication and wireless inspection can be carried out.

A prober control device 401 shown in FIG. 4 is connected to a wirelessprober 403 through a cable 402 to control an operation of the wirelessprober 403. The wireless prober 403 is to have a mechanism to operate inX, Y, and Z directions with respect to the substrate 404 placed over thestage 405.

The prober control device 401 includes a host computer 600, a datatransmission portion 601 connected to the computer, a data receptionportion 602, and a stage control portion 603 as shown in FIG. 22. Theprober control device 401 can transmit test program data to the wirelessprober 403 by the data transmission portion 601. The prober controldevice 401 can receive the test program data from the wireless prober403 by the data reception portion 602. The prober control device 401 canmove the stage and the prober relatively by using the stage controlportion 603.

The wireless prober 403 can transmit test program data to the antenna406 of the appropriate wireless chip over the substrate 404 by using anincorporated wireless antenna. At this time, the prober control device401 and the stage 405 are relatively moved in X, Y, and Z directions sothat the antenna 406 of the wireless chip comes in a magnetic field ofthe wireless antenna formed by a communication signal. In specific, inthe case of a wireless chip which operates at 13.56 MHz, the wirelesschip is preferably at a distance of 2 to 3 cm from the wireless prober.

When all the wireless chips over the substrate 404 are inspected,throughput of the inspection step can be improved by, for example,fixing the stage 405 and operating the wireless prober 403 in adirection shown by an arrow over the substrate 404 since moving distanceof the wireless prober 403 is short. Moreover, the wireless prober 403may be fixed and the stage 405 may be moved in a direction shown by anarrow.

The wireless prober 403 can transmit test program data to the antenna406 of the appropriate wireless chip and can transmit the inspectionresult received after the inspection to the prober control device 401through the cable 402.

As for the inspection result, a defect distribution over the substratecan be determined at a glance by showing a non-defective unit as ∘ and adefective unit as x. As the inspection result, the positions of thenon-defective and defective units may be displayed by coordinates (x, y)or the number of non-defective and defective units may be displayed aswell.

FIG. 23 is a flow chart of the inspection method. When the host computer600 starts inspection (start 630), it moves the stage 405 to aninspection position (move the stage to an inspection position 631).After that, the host computer 600 transmits test program data to thedata transmission portion 601 of the prober control device 401 (transmittest data to the data transmission portion 632). In specific, the datatransmission portion 601 transmits the test program data to theappropriate wireless chip by the wireless prober 403. Next, the datareception portion 602 receives data from an appropriate wireless chipthrough a wireless prober and the host computer 600 receives datacollected from the data reception portion 602 (receive data collectedfrom the data reception portion 633). After that, the host computer 600determines a test result to decide if the data matches or does not match(test result determination 634). If the inspection result is favorable(YES), stage coordinate data of the inspection position and an “OK” flagare stored in the host computer 600 (store stage coordinate data and“OK” 636). Then, the inspection is terminated (termination 638). On theother hand, if the inspection result is defective (NO), a retest may becarried out to make a determination (retest determination 635). In thecase where the inspection result is defective (NO) even when the retestis carried out, stage coordinate data of the target position and an “NG”flag are stored in the host computer 600 (stage coordinate data and “NG”are stored 637). Then, the inspection is terminated (termination 638).The retest may be carried out as many times as required if only theretest is carried out twice or more including the first test. Bycarrying out the inspection a plurality of times, precision of test canbe enhanced. Therefore, even when the inspection result is favorable(YES), a retest may be performed.

Next, an inspection device of a different mode is described. FIG. 6shows a structure of an inspection device which can transmit and receivecommunication signals by a prober and perform an operation inspection ofthe wireless chip in addition to the inspection device shown in FIG. 4.

A prober control device 411 shown in FIG. 6 is connected to a wirelessprober 413 through a cable 412 and controls an operation of the wirelessprober 413 which includes a prober 416. The wireless prober 413 may beprovided with a mechanism which operates in X, Y, and Z directions withrespect to a substrate 414 placed over a stage 415. That is, it is onlyrequired that the prober control device 411 and the stage 415 can moverelatively in X, Y, and Z directions similarly to FIG. 4.

The substrate 414 is provided with an electrode pad 417. FIG. 8 is a topplan view of a substrate to be inspected by using the inspection device.A large amount of wireless chips are formed over a substrate 420, theelectrode pad 417 is provided in a portion of the substrate 420, and thewireless chip includes an antenna 419. By directly connecting the prober416 and the electrode pad 417 to contact so as to be electricallyconnected by such inspection device, communication signals containingtest program data can be transmitted to the wireless chip as well.

By an inspection device of such a mode, a wireless chip can be inspectedeven when the antenna 419 over the substrate 420 has a defect and cannotbe used.

According to the aforementioned mode, in a wireless chip which transmitsand receives communication data by supplying a power source voltage byan induced electromotive force from communication signals, inspectioncontents can be flexibly changed as required by transmitting a testprogram as communication signals for every inspection when carrying outan operation inspection of a component of the wireless chip. In aconventional wireless chip incorporating an inspection circuit, a maskis required to be changed and remanufactured every time the inspectioncontents are changed. By using the invention, the inspection contentscan be flexibly changed without changing nor remanufacturing a mask. Asa result, manufacturing cost of a wireless chip can be reduced.

By forming a wireless chip of this embodiment mode by using a thin filmtransistor using a semiconductor thin film as an active layer, which isformed over an insulating substrate such as a glass substrate, a quartzsubstrate, or a plastic substrate, a highly functional and low powerconsumption wireless chip can be provided.

Embodiment Mode 2

This embodiment mode describes a device structure and a flow chart forrealizing a wireless chip inspection method of the invention, a blockdiagram and an element structure of a wireless chip as an inspectiontarget with reference to FIGS. 9 to 14.

FIG. 9 is a block diagram of a wireless chip as an inspection target bya wireless chip inspection method of the invention. FIG. 9 correspondsto the block diagram of the wireless chip of Embodiment Mode 1, to whicha liquid crystal driver portion 222 is additionally provided. FIG. 9includes the data storing portion 221, the arithmetic circuit 202, thestate control register 203, the reception circuit 204, the transmissioncircuit 205, the antenna 206, the resonant circuit 207, the power sourcecircuit 208, the reset circuit 209, the clock circuit 210, thedemodulation circuit 211, and the modulation circuit 212 similarly toFIG. 1. The liquid crystal driver portion 222 may include a switchingelement and a liquid crystal element, and a unit for controlling lighttransmission from the top surface of the substrate to the bottom surfacethereof. The switching element can be formed using a thin filmtransistor (hereinafter also called a TFT). In specific, the liquidcrystal driver portion 222 can determine to transmit or not to transmitlight by applying a voltage to the switching element in accordance withthe test result when the arithmetic circuit 202 executes a test program,thereby controlling liquid crystal molecules.

FIGS. 10 and 11 schematically show operations of liquid crystalmolecules which constitute the liquid crystal driver portion 222. Theseschematic views show a display principle of liquid crystals, which isgenerally called a TN (Twisted Nematic) type.

In FIG. 10, liquid crystal elements including a liquid crystal molecule1002 are shown between a first polarizing plate 1001 provided for afirst substrate 1004 and a second polarizing plate 1003 provided for asecond substrate 1005. When a voltage is not applied to the liquidcrystal elements, light incident from the first substrate 1004 transmitsto the second substrate 1005. In specific, only the components of onedirection of the incident light from the first substrate 1004 transmitby the first polarizing plate 1001, and are twisted at 90° in a spiraldirection by the liquid crystal molecule 1002 and transmit through thesecond polarizing plate 1003 as twisted light, thereby light transmitsfrom the first substrate 1004 to the second substrate 1005.

In FIG. 11, liquid crystal elements including a liquid crystal molecule1012 are shown between a first polarizing plate 1011 provided for afirst substrate 1014 and a second polarizing plate 1013 provided for asecond substrate 1015. When a voltage is applied to the liquid crystalelements, light incident from the first substrate 1014 does not transmitto the second substrate 1015. In specific, only the components of onedirection of the light incident from the first substrate 1014 transmitby the first polarizing plate 1011, however, it is blocked by the liquidcrystal molecule 1012. Therefore, the light does not reach the secondsubstrate 1015.

FIG. 12 is a sectional view of the liquid crystal driver portion 222. ATFT 303 is provided as a switching element over an insulating substrate301 with a base layer interposed therebetween. A source or drainelectrode of the TFT 303 is connected to a pixel electrode 304 to whicha control signal from the TFT 303 is inputted. An alignment film 305 isprovided so as to cover the pixel electrode 304 and the TFT 303. Thetilts of liquid crystal molecules can be controlled by using thealignment film 305.

A counter substrate 314 is provided so as to oppose the insulatingsubstrate 301. A counter electrode 318 and an alignment film 315 aresequentially provided over the counter substrate 314. A liquid crystalmolecule 317 is provided between the insulating substrate 301 and thecounter substrate 314. A space between the insulating substrate 301 andthe counter substrate 314 is kept constant by a spacer 319. After theliquid crystal molecule 317 is provided, the insulating substrate 301and the counter substrate 314 are fixed by a sealing material 320.

In such a liquid crystal driver portion 222, a voltage is applied to theliquid crystal molecule 317 by switching of the TFT 303. When the TFT303 is off, transmitted light 330 reaches the insulating substrate 301.

Next, an operation of a test program of a wireless chip including theliquid crystal driver portion 222 is described with reference to FIG.13.

The arithmetic circuit 202 included in a wireless chip starts anoperation by receiving the state of the state control register 203(start 307). The arithmetic circuit 202 reads a test program from thedata storing portion 221 (test program read 308) and executes a testroutine in the test program (test routine execution 309). The arithmeticcircuit 202 determines an execution result of the test routine (testresult determination 310) and applies a voltage to the liquid crystaldriver portion 222 when an abnormality is detected (voltage applicationto liquid crystal driver portion 313). At last, the arithmetic circuit202 terminates the operation (termination 312).

By executing a test program in this manner to apply a voltage to theliquid crystal driver portion 222 in accordance with a test result,transmission and non-transmission of light can be controlled.

An inspection device and an inspection method of a wireless chip whichhave the configuration shown in FIG. 9 and can operate in accordancewith a test program by the procedure shown in FIG. 13 is described withreference to FIGS. 14A and 14B. This inspection device is used incombination with the device described in Embodiment Mode 1. A structureto use an induced electromotive force from communication signals as anoperation power source of the wireless chip is similar to EmbodimentMode 1; therefore, description thereof is omitted here.

A laser light source 50 shown in FIG. 14A is emitted in a perpendiculardirection to an appropriate wireless chip 54 formed over an insulatingsubstrate 53 and transmits through the wireless chip 54 to reach a lightreceptor 51. Therefore, the laser light source 50 and the light receptor51 are required to have the same central axis.

The insulating substrate 53 and the laser light source 50 relativelymove so that the laser light source incidents in the wireless chip 54 asan inspection target. For example, a unit for moving a stage to hold theinsulating substrate 53 in X and Y directions may be provided.

Inside a spacer 57 of the wireless chip 54 is filled with a liquidcrystal 56 which is controlled to transmit or not to transmit light bythe liquid crystal driver portion 222. The insulating substrate 53 isdivided in a cut region 58 after the inspection by the inspectiondevice.

When light is emitted from the laser light source 50 to the appropriatewireless chip 54, the liquid crystal is driven if an execution result ofa test program is normal, and thus a light of the laser light source 50can not reach the light receptor 51. When the execution result of aninspection program is abnormal, the liquid crystal is not driven and thelight emitted from the laser light source 50 reaches the light receptor51. The light receptor 51 stores transmission or non-transmission forevery chip and accumulates the data as defective data of the chip.

At this time, as the distance between the wireless chips 54 is narrow,anti-collision treatment is employed. By the anti-collision treatment,inspection can be carried out for only a specific wireless chip. Theanti-collision treatment may be applied in the inspection device. It isto be noted that the anti-collision treatment is treatment forpreventing the interference of signals.

As described above, a wireless chip can be inspected to be non-defectiveor defective depending on whether the light emitted from the laser lightsource 50 transmits or does not transmit therethrough.

In a wireless chip with the aforementioned mode, which is supplied witha power source voltage by an induced electromotive force fromcommunication signals and transmits and receives communication data, anoperation inspection can be carried out by the driving condition of theliquid crystals in the case of an operation inspection of the componentsof the wireless chip. Therefore, a result is not transmitted bycommunication, but detected by transmission or non-transmission oflight. As a result, the wireless chip is not affected by an electricnoise generated from the device in the inspection step.

When the inspection method described in this embodiment mode is used formanufacturing a wireless chip incorporating a liquid crystal displayelement, operation inspection of a display element and a wireless chipcan be simultaneously carried out. Therefore, the number of inspectionsteps can be reduced and manufacturing cost can be reduced as well.

When the wireless chip of this embodiment mode is formed using a thinfilm transistor formed of a semiconductor thin film as an active layerwhich is formed over a substrate having an insulating surface, such as aglass substrate, a quartz substrate, and a plastic substrate, a highlyfunctional and low power consumption wireless chip can be provided.

FIG. 14B shows an enlarged view and a dividing step of a wireless chip.The liquid crystal 56 sandwiched between the substrates is provided overthe wireless chip 54 provided over the insulating substrate 53. Aboundary between the adjacent wireless chips is partitioned by thespacer 57. Therefore, the liquid crystal 56 is not provided over aplurality of wireless chips. In order to achieve such a structure, thespacer 57 is provided over the substrate to sandwich the liquid crystal56, the liquid crystal is dropped thereon, and the counter substrate isused to seal it. By dropping the liquid crystal in this manner, a liquidcrystal element can be provided in a plurality of regions partitioned bythe spacer 57.

After that, the substrate is divided with the wireless chip 54 and theliquid crystal element combined with each other. The substrate isdivided in a region between the spacers 57 by a laser cut method, ascribing method, or the like.

By using the invention in this manner, a wireless chip which can besimply inspected can be provided.

Embodiment Mode 3

In this embodiment mode, a test routine in a test program for realizingan inspection method of a wireless chip of the invention is describedwith reference to FIGS. 16 to 21B. A test routine of this embodimentmode can be incorporated in the test program used in Embodiment Modes 1and 2.

An operation of the test routine is described with reference to the flowchart of FIG. 16.

The arithmetic circuit 202 reads a test program from the data storingportion 221 and starts a test routine (start 501). The arithmeticcircuit 202 determines a command code of the data storing portion(command code determination 502) and branches the process into a datacopy routine (data copy routine 504), a ROM test routine (ROM testroutine 505), and a RAM test routine (RAM test routine 506) depending onthe kind of the command code, thereby any of the routines can beexecuted. It is needless to say that a plurality of the routines may beexecuted as well. At last, the arithmetic circuit 202 terminates a testroutine (termination 503).

FIG. 20 shows an address space of the data storing portion 221. The datastoring portion 221 includes a ROM 250, a RAM 251, a control register252, a reception data register 253, and a transmission data register254. The control register 252 includes a function to show any of areception processing state, a data executing state, and a transmissionprocessing state. The reception data register 253 has a function tostore data received by the wireless chip. The transmission data register254 has a function to store data transmitted by the wireless chip.Further, a reader/writer device which gives and receives data or powerto/from the wireless chip also stores similar contents to FIG. 20.

Next, the processes for the respective command codes included in FIG. 16are described in details with reference to the flow charts in FIGS. 17to 19.

FIG. 17 shows a flow chart of the data copy routine. The data copyroutine is started depending on the kind of a command (start 605). Afterthat, the reception data register is copied to the transmission dataregister (reception data register is copied to transmission dataregister 606). By copying the reception data register to thetransmission data register, data becomes capable of wirelesscommunication. Therefore, the data can be transmitted to a reader/writerdevice. Thereafter, the data is compared to the data stored in thereader/writer device to decide if the data match or do not match. Thus,the data copy routine is terminated (termination 607).

Such data copy routine can decide if original data and data to be copiedmatch or do not match and can carry out an inspection simply. Further, awire which generates a defect can be specified by the data of anon-match portion, therefore, the defect can be selectively fixed.

FIG. 18 is a flow chart of the ROM test routine. The ROM test routine isstarted depending on the kind of a command (start 611). Data of aselected address is copied to the transmission data register (data ofselected address is copied to transmission data register 612). Bycopying the data of the selected address to the transmission dataregister, the data becomes capable of wireless communication. Therefore,the data can be transmitted to a reader/writer device. Thereafter, thedata is compared to the address data stored in the reader/writer deviceto decide if the data match or do not match. Thus, the ROM test routineis terminated (termination 613).

Such ROM test routine can decide if original data and data to be copiedmatch or do not match and can carry out an inspection simply. Theinspection is carried out for an arbitrary address, but is not requiredto be carried out for all the addresses. The inspection is carried outby specifying an address in consideration of the probability of defectgeneration. It is needless to say that the inspection may be carried outfor all the addresses as well. In that case, a wire generating a defectcan be specified and selectively fixed.

FIG. 19 is a flow chart of the RAM test routine. The RAM test routine isstarted depending on the kind of a command (start 621). The data of thereception data register is copied to an appropriate address of the RAM(data of reception data register is copied to an appropriate address ofRAM 622), and the data is read from the RAM (data is read from RAM 623).Next, the copied write data and the read data are decided to match ornot (write data and read data are decided to match or not 624). If thosedata match (YES), an “OK” flag is written to the transmission dataregister to show that the inspection result is favorable (“OK” flag iswritten to the transmission data register 625), and thus the RAM testroutine is terminated (termination 627). On the other hand, if thosedata do not match (NO), an “NG” flag is written to the transmission dataregister to show that the inspection result is defective (“NG” flag iswritten to the transmission data register 626), and thus the RAM testroutine is terminated (termination 627).

The RAM test routine is a very important inspection since the RAM has afunction to temporarily store an arithmetic result of a CPU. Further, aRAM has less capacity than a ROM, therefore, the inspection of a RAM iscompleted in a short period of time.

In order to carry out such inspection, data transmitted from thereader/writer device (R/W) to the wireless chip contains SOF 260, a flag261, a command 262, data 263, CRC (Cyclic Redundancy Check) 264, and EOF265 (see FIG. 21A). The command 262 can determine which test program tobe executed.

Data transmitted from the wireless chip to the reader/writer (R/W)contains SOF 268, data 269, and EOF 270 (see FIG. 21B). The data 269 isdata to decide if the data copied to the transmission data register,that is the data stored in the reader/writer device match or not.

In the inspection described in this embodiment mode, data copied to thetransmission data register and data stored in the reader/writer devicemay be decided to match or not a plurality of times. By conducting thedecision a plurality of times, precision of the inspection can beenhanced.

With the aforementioned mode, in a wireless chip which is supplied witha power source voltage by induced electromotive force from communicationsignals and transmits and receives communication data, the wireless chipcan be inspected in a short period of time in the case of an operationinspection of the components of an RF chip. Therefore, time required forthe inspection step can be reduced, which can reduce the tact time ofthe inspection step and time required for manufacture. As a result, costcan be reduced.

When the wireless chip of this embodiment mode is formed using a thinfilm transistor formed of a semiconductor thin film as an active layerwhich is formed over a substrate having an insulating surface such as aglass substrate, a quartz substrate, and a plastic substrate, a highlyfunctional and low power consumption wireless chip can be provided.

Embodiment Mode 4

In this embodiment mode, a manufacturing method of a wireless chipconstituted by a thin film transistor formed over an insulatingsubstrate is described.

As shown in FIG. 15A, an insulating substrate 100 is prepared. A glasssubstrate, a quartz substrate, a plastic substrate, or the like can beused as the insulating substrate 100. Further, these substrates can beformed thinner by polishing the back surface or the like. Moreover, asubstrate formed by providing a layer of an insulating material over aconductive substrate formed of a metal element or the like or asemiconductor substrate formed of silicon or the like can be used aswell. By forming a wireless chip over, for example, a plastic substrate,a highly flexible, lightweight, and thin device can be manufactured.

A peeling layer 101 is selectively formed over the insulating substrate100. The peeling layer 101 may be formed over the entire surface of theinsulating substrate 100. The peeling layer 101 is formed of a singlelayer or stacked layers of a layer formed of an element selected fromtungsten (W), molybdenum (Mo), titanium (Ti), tantalum (Ta), niobium(Nb), nickel (Ni), cobalt (Co), zirconium (Zr), zinc (Zn), ruthenium(Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), orsilicon (Si), an alloy material or a compound material containing theaforementioned element as a main component. A crystal structure of alayer containing silicon is not particularly limited, but any ofamorphous, microcrystal, and polycrystal structures can be employed.

A base layer 102 is formed over the peeling layer 101. The base layer102 can be formed of a single layer or stacked layers of an insulatingmaterial such as silicon oxide, silicon nitride, or silicon oxynitride.In the case of stacking layers, a silicon oxynitride layer is formedwith a thickness of 10 to 200 nm (preferably 50 to 100 nm) as a firstlayer of the base layer 102. The silicon oxynitride layer can be formedby using SiH₄, NH₃, N₂O, and H₂ as a reaction gas by a plasma CVDmethod. Subsequently, a silicon oxynitride layer is formed with athickness of 50 to 200 nm (preferably 100 to 150 nm) as a second layerof the base layer 102. The silicon oxynitride layer can be formed byusing SiH₄ and N₂O as a reaction gas by a plasma CVD method.

A semiconductor layer 104 is formed over the base layer 102. Thesemiconductor layer 104 can be formed of silicon, a material formed ofsilicon and germanium, or the like. A crystal structure of thesemiconductor layer 104 is not particularly limited, but any ofamorphous, microcrystal, and polycrystal structures may be used.

In the case of forming the semiconductor layer 104 using a polycrystalmaterial, heat treatment is to be performed to an amorphoussemiconductor layer. One or a plurality of laser irradiation, a heatingfurnace, lamp irradiation, and the like can be used for the heattreatment.

For laser irradiation, a continuous wave type laser beam (CW laser) or apulsed wave type laser beam (pulsed laser) can be used. As the laserbeam, a laser beam emitted from one or a plurality of Ar laser, Krlaser, excimer laser, YAG laser, Y₂O₃ laser, YVO₄ laser, YLF laser,YAlO₃ laser, glass laser, ruby laser, alexandrite laser, Ti: sapphirelaser, copper vapor laser, and gold vapor laser can be used. Byirradiating the amorphous semiconductor layer with a fundamental wave ofsuch a laser beam and any of a laser beam with high harmonic such assecond to fourth harmonic of the fundamental wave, a silicon layerhaving crystals with a large grain size can be obtained. As theharmonic, a second harmonic (532 nm) or a third harmonic (355 nm) of Nd:YVO₄ laser (fundamental wave: 1064 nm) is preferably used. The laserrequires a power density of approximately 0.01 to 100 MW/cm²(preferably, approximately 0.1 to 10 MW/cm²). The laser is emitted at ascanning rate of approximately 10 to 2000 cm/sec.

A CW laser of a fundamental wave and a CW laser of a harmonic may beused for irradiation, or a CW laser of a fundamental wave and a pulsedlaser of a harmonic may be used for irradiation. By using a plurality oflaser light, a wide range of energy region can be treated.

It is also possible to use a pulsed laser beam with such a repetitionrate that an amorphous silicon layer melted by a laser beam can beirradiated with the next pulsed laser beam before being solidified. Byusing a laser beam with such a repetition rate, a silicon layer withcrystal grains that are continuously grown in the scan direction can beobtained. The repetition rate of such a laser beam is 10 MHz or higher,which is a much higher rate than that of tens to hundreds of Hz of anormally used laser beam.

When an annealing furnace is used for heat treatment, an amorphoussilicon layer is heated at a temperature of 400 to 550° C. for 2 to 20hours. At this time, the temperature is preferably set in multiplestages in the range of 400 to 550° C. so as to increase gradually.Hydrogen and the like contained in the amorphous silicon layer areexhausted in the first low temperature heating step at about 400° C.,which leads to reduction in roughness of the surface generated incrystallization.

In the aforementioned heat treatment, a metal for promoting thecrystallization of the semiconductor layer, for example nickel (Ni) isadded. When the amorphous silicon layer is coated with a solutioncontaining nickel (Ni) and subjected to the heat treatment, the heatingtemperature can be reduced and a polycrystalline silicon layer with acontinuous crystal grain boundary can be obtained. As a metal forpromoting the crystallization, nickel (Ni) as well as iron (Fe),ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir),platinum (Pt), copper (Cu), silver (Au), and the like may be employed.

Since the metal for promoting the crystallization becomes a source ofpollution of a memory cell or the like, a gettering step for removingthe metal is desirably performed after the semiconductor layer iscrystallized. In the gettering step, after the semiconductor layer iscrystallized, a layer functioning as a gettering sink is formed over thesemiconductor layer and heated, so that the metal moves to the getteringsink. As the gettering sink, a polycrystalline semiconductor layer or asemiconductor layer to which an impurity is added can be used. Forexample, a polycrystalline silicon layer to which an inert element suchas argon is added may be formed over the silicon layer so as to be usedas the gettering sink. When the inert element is added to the getteringsink, distortion occurs and the metal can be captured more efficiently.Alternatively, the metal may be captured by adding an element such asphosphorus to a part of a semiconductor layer of a TFT without forming agettering sink.

The thus formed semiconductor layer 104 is processed into apredetermined shape, thereby forming an island shape semiconductor layer104. The processing is performed by etching using a mask that is formedby photolithography. As the etching, wet etching or dry etching can beused.

An insulating layer functioning as a gate insulating layer 105 is formedso as to cover the semiconductor layer 104. The gate insulating layer105 can be formed using similar material and method to the base layer102.

As shown in FIG. 15B, a conductive layer functioning as a gate electrodelayer 106 is formed with the gate insulating layer 105 interposedtherebetween. The gate electrode layer 106 can be formed using a filmformed of aluminum (Al), titanium (Ti), molybdenum (Mo), tantalum (Ta),tungsten (W), or silicon (Si), or an alloy film containing theseelements. The gate electrode layer 106 can have a single layer structureor a stacked-layer structure. As the stacked-layer structure, tantalumnitride and tungsten may be stacked. The gate electrode layer 106 isprocessed by etching using a mask which is formed by photolithography.As the etching, wet etching or dry etching can be used.

A sidewall 107 which functions as an insulating layer is formed on aside surface of the gate electrode layer 106. The sidewall 107 can beformed using similar material and method to the base layer 102. An edgeportion of the sidewall 107 may be tapered by anisotropic etching. Ashort channel effect is particularly remarkable in an n-channel TFT,therefore, the sidewall 107 is preferably provided on a side surface ofa gate electrode of an n-channel TFT.

In such a state, the gate insulating layer 105 is etched. As a result, aportion of the semiconductor layer 104 and the base layer 102 areexposed. As the etching, wet etching or dry etching can be used.

With the gate electrode layer 106 and the sidewall 107, an impurityelement is added to the semiconductor layer 104 to form highconcentration impurity regions 110 and 112. In the case of forming ann-channel TFT, phosphorus is used as the impurity element while boron isused in the case of forming a p-channel TFT. At this time, it ispreferable to control the amount of impurity element to form a lowconcentration impurity region under the sidewall 107. In this embodimentmode, a low concentration impurity region 111 is formed in only animpurity region of an n-channel TFT. The low concentration impurityregion 111 can prevent a short channel effect. A TFT structure havingsuch a low concentration impurity region is called an LDD (Lightly DopedDrain) structure.

After that, an insulating layer 114 is formed so as to cover the baselayer 102, the semiconductor layer 104, the gate electrode layer 106,and the sidewall 107. The insulating layer 114 may be formed of siliconoxide, silicon nitride, or the like by a CVD method.

After forming the insulating layer 114, heat treatment is performed asrequired. The heat treatment can be carried out similarly to theaforementioned crystallization. By this heat treatment, the impurityregions are activated. The insulating layer 114 formed by a CVD methodcontains a lot of hydrogen, therefore, the heat treatment can dispersesthe hydrogen, which leads to reduction in roughness of a film in theimpurity regions.

As shown in FIG. 15C, insulating layers 115 and 116 which function asinterlayer insulating films are formed. An inorganic material or anorganic material can be used for the insulating layers 115 and 116. Asthe inorganic material, silicon oxide, silicon nitride, siliconoxynitride, or the like can be used. As the organic material, polyimide,acrylic, polyamide, polyimide amide, benzocyclobutene, siloxane, orpolysilazane can be used. It is to be noted that siloxane has a skeletonstructure formed of a bond of silicon (Si) and oxygen (O). As asubstituent, an organic group containing at least hydrogen (for example,an alkyl group or aromatic hydrocarbon) is used. As the substituent, afluoro group may also be used. In addition, an organic group containingat least hydrogen and a fluoro group may be used as the substituent.Polysilazane is formed of a polymer material including a bond of silicon(Si) and nitrogen (N) as a starting material. In general, when using aninorganic material, an impurity element can be prevented from entering,while flatness can be enhanced when using an organic material.Therefore, in this embodiment mode, an inorganic material is used forthe insulating layer 115 and an organic material is used for theinsulating layer 116.

Next, openings are formed in the insulating layers 114, 115, and 116 byetching, thereby forming a wire 118 through a contact hole. The wire 118can be formed of a film formed of an element selected from aluminum(Al), titanium (Ti), molybdenum (Mo), tantalum (Ta), tungsten (W), orsilicon (Si) or an alloy film containing these elements. The wire 118can be formed of a single layer or stacked layers. For example,tungsten, tungsten nitride, or the like as a first layer, an alloy ofaluminum and silicon (Al—Si) or an alloy of aluminum and titanium(Al—Ti) as a second layer, and a titanium nitride film, a titanium film,or the like as a third layer may be sequentially stacked. The wire 118is processed by etching using a mask which is formed byphotolithography. As the etching, wet etching or dry etching can beused. The wire 118 is connected to the high concentration impurityregions 110 and 112 of the semiconductor layer 104.

In this manner, an n-channel TFT 130 and a p-channel TFT 131 can beformed.

After that, a protective layer 119 is formed over the wire 118 asrequired. The protective layer 119 can be formed of silicon oxide,silicon nitride, or the like. For example, the protective layer 119 isformed of silicon nitride. As a result, the TFT is protected.

Here, as shown in FIG. 15D, an opening portion is formed at a desiredposition in a region where a TFT is not formed, and etchant 125 isintroduced in the opening portion. The opening portion can be formed bywet etching or dry etching. For the etchant 125, a material suitable forthe quality of the layer to be etched is selected, that is a materialsuitable for the peeling layer. For example, for wet etching, a mixedsolution in which hydrofluoric acid is diluted with ammonium fluoride, amixed solution of hydrofluoric acid and nitric acid, a mixed solution ofhydrofluoric acid, nitric acid, and acetic acid, a mixed solution ofhydrogen peroxide and sulfuric acid, a mixed solution of hydrogenperoxide, an ammonium solution, and water, a mixed solution of hydrogenperoxide, hydrochloric acid, and water, or the like can be used. For dryetching, a gas containing halogen-based atoms or molecules such asfluoride or a gas containing oxygen is used. It is preferable to use agas or a solution containing halogen fluoride or an interhalogencompound, for example, chlorine trifluoride (ClF₃) as the etchant.

By introducing the etchant 125, the peeling layer 101 is removed. Then,the insulating substrate 100 is peeled off. In this manner, a thin andlightweight wireless chip can be manufactured.

In addition to the aforementioned methods, the etchant may be introducedby exposing the peeling layer 101 by a method such as laser drawing orcutting a side of the wireless chip. Further, the insulating substrate100 may be physically peeled off without using the etchant.

As shown in FIG. 15E, by covering the TFT, which is peeled off, withfilms 127 and 128, a wireless chip is completed. At this time, the films127 and 128 may be attached by using an adhesive layer 129. A protectivelayer may be formed over the films 127 and 128 to prevent moisture,oxygen, or the like from entering. As the protective layer 119 is formedover the wire 118, a protective film may be formed under the base layer102 or the adhesive layer 129. The protective film can be formed ofsilicon oxide, silicon nitride, or the like.

The wireless chip formed over the insulating substrate and peeled offthe insulating substrate can be provided with lightweight and at lowcost. Further, as such a wireless chip is highly flexible, it can beattached to a curved surface and mounted on various objects.

Embodiment Mode 5

This embodiment mode describes a wireless chip having an encryptionfunction with reference to FIGS. 24 to 26 as an example of asemiconductor device of the invention. FIG. 24 is a block diagram of thewireless chip, FIG. 25 is a layout diagram of the wireless chip, andFIG. 26 is a sectional view of a portion of the wireless chip.

First, a block configuration of the wireless chip is described withreference to FIG. 24. In FIG. 24, a wireless chip 2601 includes anarithmetic circuit 2606 constituted by a CPU 2602, a ROM 2603, a RAM2604, and a controller 2605, and an analog portion 2615 constituted byan antenna 2607, a resonant circuit 2608, a power source circuit 2609, areset circuit 2610, a clock generating circuit 2611, a demodulationcircuit 2612, a modulation circuit 2613, and a power source managingcircuit 2614. The controller 2605 is constituted by a CPUIF 2616 as aninterface of the CPU, a control register 2617, a code extracting circuit2618, and an encoding circuit 2619. It is to be noted in FIG. 24 thatcommunication signals are shown as different signals for simplicity as areception signal (encoded text) 2620 and a transmission signal (plaintext) 2621, however, they are actually combined and simultaneouslytransmitted and received between the wireless chip 2601 and areader/writer device. The reception signal (encoded text) 2620 isdemodulated by the demodulation circuit 2621 after being received by theantenna 2607. The transmission signal (plain text) 2621 is transmittedfrom the antenna 2607 after being modulated by the modulation circuit2613. It is to be noted that the plain text refers to a signalcontaining no encoded text.

In FIG. 24, when the wireless chip 2601 is placed in a magnetic fieldformed by a communication signal, an induced electromotive force isgenerated by the antenna 2607 and the resonant circuit 2608. The inducedelectromotive force is held by electric capacitance of the power sourcecircuit 2609, stabilized in potential by the electric capacitance, andsupplied as a power source voltage to each circuit in the wireless chip2601. The reset circuit 2610 generates a reset signal for initializingthe whole wireless chip 2601. For example, a signal which rises with adelay to a rise of the power source voltage is generated as a resetsignal. The clock generating circuit 2611 changes a frequency and a dutyratio of a clock signal in accordance with a control signal generated bya power source managing circuit 2614. The demodulation circuit 2612detects a change in amplitude of the reception signal (encoded text)2620 of an ASK method as reception data 2622 of “0” or “1”. For example,a low pass filter is used as the demodulation circuit 2612. Thedemodulation circuit 2613 transmits transmission data by changing theamplitude of the transmission signal (plain text) 2621 of an ASK method.For example, when transmission data 2623 is “0”, a resonance point ofthe resonant circuit 2608 is changed so as to change the amplitude ofthe communication signal. The power source managing circuit 2614 managesa power source voltage supplied from the power source circuit 2609 tothe arithmetic circuit 2606 and the current consumption at thearithmetic circuit 2606, and generates a control signal for changing thefrequency and the duty ratio of the clock signal at the clock generatingcircuit 2611.

An operation of a wireless chip of this embodiment mode is described.First, the reception signal (encoded text) 2620 containing encoded textdata is received by the wireless chip 2601. The reception signal(encoded text) 2620 is demodulated by the demodulation circuit 2612,divided into a control command, the encoded text data, and the like bythe code extracting circuit 2618, and stored in the control register2617. Here, the control command is data to specify a response of thewireless chip 2601. For example, transmission of a specific ID,operation stop, encryption, or the like is specified. Here, a controlcommand for encryption is received.

Subsequently, in the arithmetic circuit 2606, the CPU 2602 decrypts(decodes) the encoded text by using a secret key 2624 stored in the ROM2603 in advance in accordance with a decryption program stored in theROM 2603. The decoded text is stored in the control register 2617. Atthis time, the RAM 2604 is used as a data storing region. It is to benoted that the CPU 2602 accesses the ROM 2603, the RAM 2604, and thecontrol register 2617 through the CPUIF 2616. The CPUIF 2616 has afunction to generate an access signal for any of the ROM 2603, the RAM2604, and the control register 2617 from an address requested by the CPU2602.

At last, the transmission data 2623 is generated from the decoded textin the encoding circuit 2619 and modulated in the modulation circuit2613, thereby the transmission signal (plain text) 2621 is transmittedfrom the antenna 2607 to the reader/writer.

It is to be noted in this embodiment mode that a method to process bysoftware, that is a method to constitute an arithmetic circuit by a CPUand a large capacity memory and execute a program by the CPU is employedas an arithmetic method, however, the most suitable arithmetic methodcan be selected for application and the arithmetic circuit can beconstituted based on the selected method. For example, as the arithmeticmethod, a method to process the operation by hardware and a method touse both hardware and software can be suggested. In the method toprocess by hardware, a dedicated circuit may be used to constitute thearithmetic circuit. In the method to use both hardware and software, adedicated circuit, a CPU, and a memory may be used to constitute thearithmetic circuit, where the dedicated circuit performs a part of anarithmetic process and the CPU executes a program of the rest of thearithmetic process.

Next, a layout of a wireless chip is described with reference to FIG.25. It is to be noted in FIG. 25 that a portion corresponding to FIG. 24is denoted by the same reference numeral and the description thereof isomitted here.

In FIG. 25, an FPC pad 2707 is an electrode pad group used for attachingan FPC (Flexible Printed Circuit) to the wireless chip 2601. Antennabumps 2708 are electrode pads for attaching an antenna. It is to benoted that an excessive pressure may be applied to the antenna bumps2708 when attaching the antenna. Therefore, it is preferable not toprovide a component which constitutes a circuit such as a transistorunder the antenna bumps 2708.

The FPC pad 2707 is effectively used mainly for failure analysis. As awireless chip obtains a power source voltage by communication signals,an arithmetic circuit does not operate at all when an antenna or a powersource circuit has a defect. As a result, failure analysis is extremelydifficult when the antenna or the power source circuit has a defect.However, by supplying a power source voltage to the wireless chip 2601from the FPC through the FPC pad 2707 and inputting appropriateelectrical signals instead of electrical signals supplied from theantenna, the arithmetic circuit can be operated. Therefore, failureanalysis can be carried out even when the antenna or the power sourcecircuit has a defect.

Further, it is further effective to provide the FPC pad 2707 wheremeasurement using a prober is possible. That is, by providing theelectrode pads in the FPC 2707 in accordance with a pitch of the needlesof a prober, measurement can be carried out using the prober. By using aprober, the number of steps to attach the FPC in the failure analysiscan be reduced. Moreover, measurement can be carried out when aplurality of wireless chips are formed over a substrate, therefore, thenumber of steps to divide the substrate into each wireless chip can bereduced as well. In the case of mass production, the inspection ofwireless chips can be carried out before a step of attaching theantenna. Therefore, as a defective product can be sorted in an earlystage of the manufacturing step, manufacturing cost can be reduced.

FIG. 26 is a sectional view of such a wireless chip. First, elements upto a wire 1804 corresponding to the wire 118 shown in FIG. 15 areformed. An insulating layer 1853 is formed so as to cover the wire 1804.The insulating layer 1853 can be formed of an inorganic material or anorganic material. As the inorganic material, silicon oxide, siliconnitride, or the like can be used. As the organic material, polyimide,acrylic, polyamide, polyimide amide, benzocyclobutene, siloxane, orpolysilazane can be used. It is to be noted that siloxane has a skeletonstructure formed of a bond of silicon (Si) and oxygen (O). As asubstituent, an organic group containing at least hydrogen (for example,an alkyl group or aromatic hydrocarbon) is used. As the substituent, afluoro group may also be used. In addition, an organic group containingat least hydrogen and a fluoro group may be used as the substituent.Polysilazane is formed of a polymer material including a bond of silicon(Si) and nitrogen (N) as a starting material.

In a connecting region 1850, an opening portion is formed in theinsulating layer 1853 so that a wire 1851 formed simultaneously with thewire 1804 is exposed. It is preferable that the opening portion have topedge corner portions which are rounded and tapered sides. This canprevent a discontinuity of a pattern to be formed later.

A connecting wire 1852 is formed in the opening portion. The connectingwire 1852 can be formed of a film which is formed of an element selectedfrom aluminum (Al), titanium (Ti), molybdenum (Mo), tungsten (W), orsilicon (Si), an alloy film containing these elements, or the like.Further, a light-transmissive material such as indium tin oxide (ITO),indium tin oxide (ITSO) containing silicon oxide, or indium oxidecontaining zinc oxide by 2 to 20% can be used. At this time, theconnecting wire 1852 is arranged so as not to overlap n-channel TFTs1821 and 1822, a capacitor 1824, a resistor 1825, a p-channel TFT 1823,and the like. This prevents unexpected parasitic capacitance to begenerated.

An insulating layer 1854 is formed so as to cover the insulating layer1853 and the connecting wire 1852. The insulating layer 1854 can beformed similarly to the insulating layer 1853.

An opening portion is formed in the insulating layer 1854 so that theconnecting wire 1852 provided over the insulating layer 1853 is exposed.In the opening portion, an anisotropic conductor 1856 including aconductive particle 1855 is provided, to which an FPC 1858 having aconductive layer 1857 is connected.

In this manner, a wireless chip of the invention can be manufactured.

Embodiment Mode 6

An antenna may have a size and a shape suitable for the application andin a range determined by Wireless Telegraphy Act. A signal to betransmitted and received has a frequency of 125 kHz, 13.56 MHz, 915 MHz,2.45 GHz, or the like, which is standardized by ISO standard or thelike. For the antenna, a dipole antenna, a patch antenna, a loopantenna, a Yagi antenna, or the like may be used. In this embodimentmode, a shape of an antenna connected to the wireless chip is described.

FIG. 27A shows an antenna 1602 connected to a wireless chip 1601. InFIG. 27A, the wireless chip 1601 is provided in a center portion and theantenna 1602 is connected to a connecting terminal of the wireless chip1601. In order to secure the length of the antenna, the antenna 1602 isfolded at a plurality of portions.

In FIG. 27B, the wireless chip 1601 is provided on one end side and anantenna 1603 is connected to a connecting terminal of the wireless chip1601. In order to secure the length of the antenna, the antenna 1603 isfolded at a plurality of portions.

In FIG. 27C, an antenna 1604 having a plurality of folded portions isprovided at both ends of the wireless chip 1601.

In FIG. 27D, a linear antenna 1605 is provided at both ends of thewireless chip 1601.

In this manner, a shape of an antenna may be selected to be suitable fora structure, a polarized wave, or an application of a wireless chip.Therefore, a folded dipole antenna may be used for the dipole antenna. Acircular loop antenna or a square loop antenna may be used as the loopantenna. A circular patch antenna or a square patch antenna may be usedas the patch antenna.

In the case of using a patch antenna, an antenna formed of a dielectricmaterial such as ceramic may be used. By setting a dielectric constantof a dielectric material to be used as a substrate for the patchantenna, the antenna can be downsized. Moreover, as a patch antenna hasa high mechanical strength, it can be used repeatedly.

A dielectric material of a patch antenna can be formed of ceramic, anorganic resin, a mixture of ceramic and an organic resin, or the like. Atypical example of ceramic is alumina, glass, forstelite, or the like.Moreover, a plurality of ceramic may be mixed to be used. In order toobtain a high dielectric constant, it is preferable to form a dielectriclayer using a ferroelectric material. A typical example of aferroelectric material is barium titanate (BaTiO₃), lead titanate(PbTiO₃), strontium titanate (SrTiO₃), lead zirconate (PbZrO₃), lithiumniobate (LiNbO₃), zircon lead titanate (PZT), or the like. Furthermore,a plurality of ferroelectric materials may be mixed to be used.

The aforementioned embodiment modes and the structure described thereincan be applied to the wireless chip 1601.

Embodiment 1

In this embodiment, the method described in Embodiment Mode 5 is used tocarry out a test, thereby measurement was carried out by a spectrumanalyzer. A response signal was outputted with respect to an RF signalhaving a frequency of 13.56 MHz, which was inputted to a wireless chip.

FIGS. 28A to 28C show measurement results of transmission/receptionsignal waveforms of a wireless chip, which were measured by a spectrumanalyzer. A gain-frequency measurement result shown in FIG. 28B showsfrequency characteristics gained by the wireless chip. The frequency isshown by the horizontal axis while the gain is shown by the verticalaxis. There is a peak 2803 at the frequency of 13.56 MHz, which meansthat the wireless chip has high sensitivity to 13.56 MHz. FIG. 28A showsa change with time of a gain by the wireless chip at the gain-timemeasurement result frequency of 13.56 MHz. Time is shown by thehorizontal axis while the gain is shown by the vertical axis. A waveformof a region 2801 shows a transmission signal from a reader/writer to thewireless chip, which is a transmission signal (encoded text) 2620containing encoded text data. Further, a waveform of a region 2802 showsa response signal from the wireless chip to the reader/writer, which isa transmission signal (plain text) 2621. FIG. 28C shows a gain-timemeasurement result, which is an enlargement of the region 2802. FIG. 28Cshows details of the response signals from the wireless chip to thereader/writer.

According to the measurement results of this embodiment, it is effectiveto carry out a test using the method described in Embodiment Mode 5.This application is based on Japanese Patent Application serial no.2005-228639 filed in Japan Patent Office on 5th, August, 2005, theentire contents of which are hereby incorporated by reference.

1. A semiconductor device comprising: an antenna; a reception circuit operationally connected with the antenna; a state control register operationally connected with the reception circuit; and a data storing portion operationally connected with the state control register, wherein the data storing portion, the reception circuit, and the state control register each comprises a thin film transistor; wherein the data storing portion stores a test program received through the antenna by wireless communication; and wherein the state control register becomes a test program executing state.
 2. The semiconductor device according to claim 1, wherein the data storing portion includes a read only memory and a random access memory.
 3. The semiconductor device according to claim 2, wherein data of the test program comprises a test routine for carrying out an operation test of the read only memory and the random access memory.
 4. A semiconductor device comprising: an RF circuit; a reception circuit operationally connected with the RF circuit; a state control register operationally connected with the reception circuit; and a data storing portion operationally connected with the state control register; wherein the data storing portion, the reception circuit, the state control register, and the RF circuit each comprises a thin film transistor; wherein the data storing portion stores a test program received through the RF circuit by wireless communication; and wherein the state control register becomes a test program executing state.
 5. The semiconductor device according to claim 4, wherein the data storing portion includes a read only memory and a random access memory.
 6. The semiconductor device according to claim 5, wherein data of the test program comprises a test routine for carrying out an operation test of the read only memory and the random access memory.
 7. The semiconductor device according to claim 4, comprising: an arithmetic circuit and a transmission circuit, wherein the arithmetic circuit comprises a function to: start the test program after the state control register becomes a test program executing state; after the test program is terminated, set the state control register into a transmission processing state for processing transmission data so as to be suitable for a form of a communication signal, and thereafter output the transmission data to a modulation circuit by the transmission circuit; and set the state control register into a reception processing state after a transmission is terminated.
 8. An inspection method of a semiconductor device comprising: starting an operation of an arithmetic circuit in accordance with a state of a state control register; reading a test program stored in a data storing portion by the arithmetic circuit; executing a test routine in accordance with the test program; deciding an execution result of the test routine in accordance with the test program; and writing the execution result to the data storing portion in accordance with the test program, wherein the test program is received through an RF circuit.
 9. An inspection method of a semiconductor device comprising: starting a test program when or after a state control register becomes a test program executing state; reading the test program from a data storing portion by an arithmetic circuit; executing a test routine in accordance with the test program; deciding an execution result of the test routine in accordance with the test program; writing the execution result to the data storing portion in accordance with the test program; setting the state control register to a transmission processing state when or after the test program is terminated; and setting the state control register to a reception processing state by the arithmetic circuit after a transmission is terminated, wherein the test program is received through an RF circuit.
 10. An inspection method of a wireless chip comprising: receiving a test program through an RF circuit; storing the test program in a data storing portion; and after an inspection is carried out by the test program, displaying a result of the inspection by a liquid crystal element.
 11. The inspection method of a wireless chip, according to claim 10, wherein the liquid crystal element has a liquid crystal molecule sandwiched between substrates provided with a polarizing plate.
 12. An inspection method of a wireless chip comprising: receiving a test program through an RF circuit; storing the test program in a data storing portion; and after an inspection is carried out by the test program, deciding a result of the inspection by whether light from a laser light source is inputted to a light receptor or not.
 13. The inspection method of a wireless chip, according to claim 12, wherein a liquid crystal element is provided over the wireless chip, and wherein the liquid crystal element comprise a liquid crystal molecule sandwiched between substrates provided with a polarizing plate.
 14. A semiconductor device comprising: an antenna; a reception circuit operationally connected with the antenna; a state control register operationally connected with the reception circuit; and a data storing portion operationally connected with the state control register, wherein the data storing portion, the reception circuit, and the state control register each comprises a thin film transistor; wherein the data storing portion stores a test program received through the antenna by wireless communication for an operation test of the semiconductor device, and wherein the state control register becomes a test program executing state.
 15. The semiconductor device according to claim 14, wherein the data storing portion includes a read only memory and a random access memory.
 16. The semiconductor device according to claim 15, wherein data of the test program comprises a test routine for carrying out an operation test of the read only memory and the random access memory.
 17. A semiconductor device comprising: an RF circuit; a reception circuit operationally connected with the RF circuit; a state control register operationally connected with the reception circuit; and a data storing portion operationally connected with the state control register; wherein the data storing portion, the reception circuit, the state control register, and the RF circuit each comprises a thin film transistor; wherein the data storing portion stores a test program received through the RF circuit by wireless communication for an operation test of the semiconductor device; and wherein the state control register becomes a test program executing state.
 18. The semiconductor device according to claim 17, wherein the data storing portion includes a read only memory and a random access memory.
 19. The semiconductor device according to claim 18, wherein data of the test program comprises a test routine for carrying out an operation test of the read only memory and the random access memory.
 20. The semiconductor device according to claim 17, comprising: an arithmetic circuit and a transmission circuit, wherein the arithmetic circuit comprises a function to: start the test program after the state control register becomes a test program executing state; after the test program is terminated, set the state control register into a transmission processing state for processing transmission data so as to be suitable for a form of a communication signal, and thereafter output the transmission data to a modulation circuit by the transmission circuit; and set the state control register into a reception processing state after a transmission is terminated. 